Plant ID forum: What plant is this? Was found in the garden in the San Francisco Peninsula area

What plant is this? It has been growing in a pot in the garden in the San Francisco Peninsula area and has now reached four feet in height. Around five clustered stems have grown from the soil in the pot and we would like to know if it is a weed. No flowers have bloomed as yet. Thank you.

I think it may be Epilobium, but it's hard to tell.. Can you back up and get a picture of the whole plant, and maybe the flowers or buds? If it is Epilobium, the flowers should be small. I have a lot of it in Santa Cruz, but 4' seems a little on the tall side for here..